So I made a lacto 5335 starter a couple days ago. Thinking it was at too low of a temp I placed it on the heater last night, but when I woke up this morning the temp had risen to 140F. Did I kill the bacteria? Do I need to buy a new pack? Thanks.

__________________
"The ordinary world is only the foam on top of the real world." Tom Robbins (B is for Beer)
"It's a beautiful day for baseball. Let's play two." Ernie Banks

Lacto does live through the no boil procedure for a berliner weisse and that hits around 160 so I would say your guys are fine. However, I don't know enough to say if you would have any die off at 140 nor do I know if that temp will result in the lacto being stressed to the point to cause off flavors...hopefully those who know more will pipe up because I'm interested too. If not, you could get more lacto and do a split batch and experiment.

I know Lacto loves temps up to ~120 F (it will make yogurt over night at that temp). That said, when I made Sake the instructions called for pasteurzing at 140 F. This http://www.fcs.msue.msu.edu/ff/pdffiles/foodsafety2.pdf suggests that 30 min at 150 is the minimum for the pasteurization of milk (it only takes 15 seconds at 161).

Feed it some fresh wort, if it looks active you are fine, otherwise it is time for some fresh microbes.

Well I bought another pack and made a new starter just to be safe. I've decided instead of making 5 gallons I'm going to make 10 gallons and mix half of each starter into each 5 gallon carboy. Wyeast emailed me back with this:

"Some quick research of Lactobacillus thermal death curves shows a 90% death rate in 2.5 minutes at a range of 120 – 140oF. I would say if you made it up to 140 for longer than 5 minutes that at least 99% of your bacteria is dead.

No, unfortunately there is not a visual viability test for bacteria.

I am guessing if you really did hit 140 for a prolonged period of time, there is not much bacteria left to work with and it would be best to start with a new culture."

So according to them, I have definitely killed every cell.

Is it possible to chill and decant a lacto starter? If it is, I will definitely try to add some fresh wort and revive what I can.

__________________
"The ordinary world is only the foam on top of the real world." Tom Robbins (B is for Beer)
"It's a beautiful day for baseball. Let's play two." Ernie Banks

Is it possible to chill and decant a lacto starter? If it is, I will definitely try to add some fresh wort and revive what I can.

Bacteria are a lot smaller and weigh a lot less than yeast cells, and also they do not flocculate like yeast cells do through cell surface proteins, so it takes a lot more time for them to settle to the bottom. In my experience with lacto starters was It took one week in the refrigerator for a majority of the cells to settle out, but there was still quite a number of cells in the supernatant.

you might want to do some research on the growth rate for lacto, and determine what size starter you want to use. I know I have read about people using vary large starters for lacto, but I am not overly convinced about that being necessary. When I grow Bacteria in the lab they have a completely different growth rate than yeast.

I guess what I'm saying here is you might be able to get away with using a .5-1L starter of lacto and not need to decant your supernatant.

When I make my lacto starters I rig up a heating pad to my Ranco ETC and hold the temp at 100ºF over night on a stir plate, and get a vary good expansion of cells.

I've never used Lacto in my beers, but here's the temp. range from Wyeast:
Temperature Range: 60-95° F (15-35° C)

Hope that's a start.

Using 5335, we incubated at 90F for a week. Activity was only seen the first 4-5 days, then it stopped. We reduced temperature down to 70 getting ready to pitch a German Ale yeast and all of a sudden, it kicked off again fermenting. Why, I don't know/understand....

I've experienced similar things as far as flavor profiles go in some Belgians I've done lately where I had a keg chilling and removed it to the outdoors back in March where the temperature swung from 30F-70F over a couple weeks. When I put it back in the cooler, it was a much better and more complex beer. I'm starting to wonder if some of these wilder yeasts and bacteria need some temperature swings to help them fully develop. Remember, in nature, temperature isn't constant. I'm not saying this works for all beers because it obviously doesn't... but I'm just referring to some of the "wilder" things.

I just posted a thread touching on this subject in the yeast sub-forum.

My experience with 5335 is that you will know if your starter has been successful based on the smell and taste of the starter liquid. When it works, it tastes/smells clean and sour; when it doesn't work, it looks/tastes/smells like crap, as a result of something other than lacto working away. There are testimonials of successful lacto-soured beers that started off smelling like vomit, but since you're using a pure culture you should be able to avoid that.

I've had the best luck keeping the wort in the upper-80s/lower-90s. Although I hear that simple sugars are better for doing a lacto starter (i.e. cider), I have had great results using a standard starter wort. Using a mason jar, I pressed some syran wrap over the surface of the wort, covered the mouth of the jar with tin foil, let it sit and a few days later, I had a nice sour starter.

Apart from low temperatures, I would recommend stepping up your starter more gradually than you would a normal yeast starter. By that, I mean start with 500ml of liquid, then pour all of that into a larger container with another 500-1000 ml of starter liquid. I'm not sure how well the bacteria will crash out, but since you're going for a sour beer anyways, I would pitch the entire resulting starter.

Lastly, make sure that the starter is active when you pitch it. This is based on personal experience, but the less lag time the better.